It is known that organic and polymeric materials with large delocalized .pi.-electron systems can exhibit nonlinear optical response, which in many cases is a much larger response than by inorganic substrates.
In addition, the properties of organic and polymeric materials can be varied to optimize other desirable properties, such as mechanical and thermoxidative stability and high laser damage threshold, with preservation of the electronic interactions responsible for nonlinear optical effects.
Thin films of organic or polymeric materials with large second-order nonlinearities in combination with silicon-based electronic circuitry have potential as systems for laser modulation and deflection, information control in optical circuitry, and the like.
Other novel processes occurring through third-order nonlinearity such as degenerate four-wave mixing, whereby real-time processing of optical fields occurs, have potential utility in such diverse fields as optical communications and integrated circuit fabrication.
In conjugated organic systems it is significant that the origin of the nonlinear effects is the charge asymmetric polarization of the .pi.-electron cloud as opposed to displacement or rearrangement of nuclear coordinates found in inorganic materials.
Nonlinear optical properties of organic and polymeric materials was the subject of a symposium sponsored by the ACS division of Polymer Chemistry at the 18th meeting of the American Chemical Society, September 1982. Papers presented at the meeting are published in ACS Symposium Series 233, American Chemical Society, Washington, D.C. 1983.
The above-recited publications are incorporated herein by reference.
Of specific interest with respect to the present invention embodiments is prior art relating to thermoplastic polymers which exhibit solubility properties that encompass a broad compatibility range with both hydrophilic and hydrophobic types of organic solvents. Such thermoplastic polymers generally contain recurring units of at least one water-soluble monomer such as acrylamide, as described in U.S. patents which include U.S. Pat. Nos. 3,070,558; 3,354,084; 3,658,734; 4,115,339; 4,254,249; 4,395,524; and 4,521,580; incorporated by reference.
A pertinent prior art reference with respect to the present invention is U.S. Pat. No. 4,428,873 which describes an electrooptical solid element comprising a low molecular weight polar substance having a Kerr type electrooptical effect, and an organic polymer substance compatible with the low molecular weight polar substance.
Other light switching or modulating optical systems of interest are described in U.S. Pat. Nos. 2,441,019; 3,215,338; 3,317,266; 4,128,496; and 4,199,698.
There is continuing research effort to develop new organic optical systems for prospective novel phenomena and devices adapted for laser frequency conversion, information control in optical circuitry, light valves and optical switches. The potential utility of organic materials with large second-order and third-order nonlinearities for very high frequency application contrasts with the bandwidth limitations of conventional inorganic electrooptic materials.
Accordingly, it is an object of this invention to provide novel organic nonlinear optical substrates.
It is another object of this invention to provide organic nonlinear optical substrates exhibiting a high .chi..sup.(2) susceptibility value.
It is another object of this invention to provide a polymeric nonlinear optical medium characterized by a high Miller's delta, and a high optical damage threshold.
It is a further object of this invention to provide an optically transparent substrate which comprises a host polymer component, and a guest organic compound component which exhibits nonlinear optical susceptibility.
Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.